Smarter land use planning and better estimates of polluted water runoff across
the 64,000 square-mile (110,000-square-kilometer) Chesapeake Bay watershed are on
the horizon thanks to new land cover maps being produced by the Mid-Atlantic
Regional Earth Science Applications Center (RESAC) at the University of Maryland.
These maps, generated by overlaying images from NASA's Landsat 7, will provide a
more precise assessment of the presence and amount of different land cover types
including residential development, wetlands, forests and crop lands.

This type of precise land cover classification has not been done before for such
an extensive region, said Goetz, university research scientist and RESAC
manager. The new maps can distinguish low-density from high-density residential
development and crop land from pasture land, as well as wetlands and different
types of forest.

Local and regional planning agencies in the Washington, D.C., area are currently
working with the RESAC on the first Landsat 7 maps (above), which are centered on the
nation's capital and the surrounding counties in Maryland and Virginia. The
Maryland Department of Planning has said it will use the maps in the state's new
"smart growth" initiative, while the parks commission in Montgomery County, Md.,
plans to assess the extent of forests in its parks.